Modern video displays, such as interactive graphics stations, enable the operator or user to perform certain operations by selecting functions from a displayed menu of possible choices. At an interactive graphics station, user controlled functions typically involve selecting a system operating capability from a menu and then selecting the location on the display image where the operation is to be carried out. While the selection of the operation from the menu typically requires only a low resolution touch detection apparatus, the selection of the location on the image at which to perform the operation often requires a high resolution touch detector or digitizer. Existing digitizers which allow the user to select the X and Y coordinates either use high resolution off-the-screen digitizers or low resolution on-the-screen devices. The off-the-screen digitizer is undesirable since the user cannot work directly with the displayed image. The on-the-screen devices typically are touch sensitive devices where the resolution is limited by the resolution of the touch detection screen matrix or the pointer or finger used to touch the screen. What is desired is an on-the-screen device having the high resolution of off-the-screen digitizers.